This is an observational nested case control study among pre-exposure prophylaxis (PrEP) observational or clinical studies. The study will assess level of adherence as measured by drug level and its relationship to renal and bone adverse events, risk of seroconversion, and resistance development in subjects taking emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) (Truvada®) for PrEP.

In the protocols of the parent PrEP observational or clinical studies, participants will have follow-up visits on average every 3 months for evaluation of adherence, HIV-1 status, renal and bone adverse events, and seroconversion. Adherence will be determined by the specific FTC/TDF drug level measurement(s) outlined in the parent protocol.

There are two case definitions: a) One-hundred-fifty subjects who seroconvert (become HIV-1 positive) and b) any subjects who either develop a protocol-defined renal adverse event (stratified by Division of AIDS [DAIDS] grading) or have a skeletal adverse event (any fracture) while taking FTC/TDF for PrEP.

Among the estimated 7,000 subjects from Truvada for PrEP observational and clinical studies all cases, defined as subjects who seroconvert and/or develop either renal or skeletal adverse events, will be identified. Randomly chosen controls on Truvada will be selected in a 3:1 ratio, from the same site, with a similar treatment duration.

Treatment adherence, as measured by drug level, to the once-daily dosing regimen of FTC/TDF for PrEP [ Time Frame: Baseline to Year 3 ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Time to onset of signs and/or symptoms of acute HIV infection before and after seroconversion during treatment [ Time Frame: Baseline to Year 3 ] [ Designated as safety issue: No ]

The time to onset of signs and/or symptoms if acute HIV infection in relation to exposure to study drug will be recorded. Signs and symptoms include fever, lymphadenopathy, pharyngitis, rash, myalgia, malaise, mouth and esophageal sores, and may also include, but less commonly, headache, nausea and vomiting, enlarged liver/spleen, weight loss, thrush, and neurological symptoms.

Time to seroconversion during during treatment [ Time Frame: Baseline to Year 3 ] [ Designated as safety issue: No ]

The time to seroconversion in relation to exposure to study drug will be recorded.

HIV-1 negative adults (any sex/gender, including transgender) who are participating in observational or clinical studies on FTC/TDF for PrEP

Eligibility

Ages Eligible for Study:

18 Years and older (Adult, Senior)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Sampling Method:

Non-Probability Sample

Study Population

Seven thousand (7000) HIV-1 negative adults (any sex/gender, including transgender) who are participating in observational or clinical studies on FTC/TDF for PrEP

Criteria

Inclusion Criteria:

Participants in an FTC/TDF for PrEP observational or clinical study

HIV-1 negative adults (any sex/gender, including transgender) in an FTC/TDF for PrEP observational or clinical study

HIV-1 negative and without signs or symptoms of acute HIV-1 infection

Exclusion Criteria:

This is an observational study and will monitor all reported seroconversions, and renal or skeletal adverse events without intervention/exclusion.

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01906255